webpack/lib/dependencies/RequireEnsureDependency.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
"use strict";
const NullDependency = require("./NullDependency");

class RequireEnsureDependency extends NullDependency {
	constructor(block) {
		super();
		this.block = block;
	}

	get type() {
		return "require.ensure";
	}
}

RequireEnsureDependency.Template = class RequireEnsureDependencyTemplate {
	apply(dep, source, runtime) {
		const depBlock = dep.block;
		const promise = runtime.blockPromise({
			block: depBlock,
			message: "require.ensure"
		});
		const errorCallbackExists =
			depBlock.expr.arguments.length === 4 ||
			(!depBlock.chunkName && depBlock.expr.arguments.length === 3);
		const startBlock = `${promise}.then((`;
		const middleBlock = ").bind(null, __webpack_require__)).catch(";
		const endBlock = `).bind(null, __webpack_require__)).catch(${runtime.onError()})`;
		source.replace(
			depBlock.expr.range[0],
			depBlock.expr.arguments[1].range[0] - 1,
			startBlock
		);
		if (errorCallbackExists) {
			source.replace(
				depBlock.expr.arguments[1].range[1],
				depBlock.expr.arguments[2].range[0] - 1,
				middleBlock
			);
			source.replace(
				depBlock.expr.arguments[2].range[1],
				depBlock.expr.range[1] - 1,
				")"
			);
		} else {
			source.replace(
				depBlock.expr.arguments[1].range[1],
				depBlock.expr.range[1] - 1,
				endBlock
			);
		}
	}
};

module.exports = RequireEnsureDependency;